From Postfix and dovecot to ZCS 6

[twistedbrain]

Sorry if the questiona has alredy been answered, but I couldn't find it and I'll be gratefull also for a big RTFM! if you tell me what is manual.

I have a mailserver (1 cpu 1,2 Ghz, 512 MB RAM and 40 GB disk) on Ubuntu 6.06 LTS with postfix 2.2.10 and dovecot 1.0 beta 3 and about 150 users. They access their maildir on the server with IMAP and clients like Outlook and Thunderbird.
Now I have a new server (a CentOS virtual machine with 2 vcpu 2,8 Ghz, 4 GB RAM and more than 100 GB of disk) and I'd like to take all users and e-mail and bring them to a new ZCS 6 server.

The mailserver should be the same (postfix), but I don't know users credential, they are managed like system users, so their password are encrypted in /etc/shadow and their emails are in /home/user_account/Maildir.

How do you advice to do to bring credentials and e-mails from the old server to the new, possibly without disturbing the users (it is they go home friday evening and on monday morning can use the e-mail without realizing that something changed?)

Thanks to replying people and best regards to everyone,

Andrea

[uxbod]

Welcome to the forums

Have a read through Mail Migration - Zimbra :: Wiki.

[twistedbrain]

Thx for the welcome and the good RTFM!

But at now I don't see easy solutions, because imapsync requires the user's passwords that I don't have and other migration paths for dovecot without password require ldap authentication and I don't have ldap.
The first things that I have to learn is exactely how ZCS authenticates users and which software and format it uses for IMAP.

Regards, Andrea

[LMStone]

Probably easiest for everyone to have the users migrate their own mail, like so:

1. Create all the users in Zimbra and assign them passwords.
2. Create a "cheat sheet" to show how users can add a second mail account to Outlook/Thunderbird; this second mail account will be their Zimbra account.
3. In the "cheat sheet" show users how to set up automatic forwarding of their emails from their existing account to their new Zimbra account.
4. In the "cheat sheet" show the users how to drag emails from their existing account into their new Zimbra account.
5. After all of the user's mail is moved, you can decommission the Postfix/Dovecot server and in the "cheat sheet", show users how to remove their old email account.
6. You are done!

In this way, not all users need to have their mail moved at the same time. You can just pick a date and say to the users that the old server will be turned off on that date, so they need to move their email anytime before then.

Hope that helps,
Mark

[fcash]

This requires a bit of planning, but can be done. You'll need some way to tell the staff what their temp password is, and how to login to the web client, in order to set their desired password.

1. Create all the accounts on the Zimbra server, set a default password, with the "change on first login" option enabled.

2. Then, reset the passwords for all the accounts on the old server to "whatever". (A simple "sed" command run against /etc/shadow can reset all the passwords in one go, and can save a copy of the original passwords.)

3. Then, use imapsync to migrate the mail over from the old server to the new server. This can be scripted quite easily.

4. Finally, turn off the old server (but keep it around, just in case).

[twistedbrain]

Thanks. I was thinking about something like that, but you show me the path.
Maybe, *maybe*, if I can integrate with this: Centralize user accounts with OpenLDAP
to reset the password after migration I can also avoid to have the users involved in the change.

Andrea

[twistedbrain]

@LMStone, thanks to you too, but you don't know my (l)users, or at least many of them. It would be a bloodbath. Less they have to do, less I have to, also if normally (with normal users) the things wouldn't be like that. Someone of them for me is like a Zen meditation exercise, it is, I'm a patient person, but after few tens seconds of support I'd like to strangle them because they are too stupid to stay alive, so please, don't suggest any more a solution that need active user's intervention :-)

Andrea

[twistedbrain]

Originally Posted by fcash

[...]
2. Then, reset the passwords for all the accounts on the old server to "whatever". (A simple "sed" command run against /etc/shadow can reset all the passwords in one go, and can save a copy of the original passwords.)

Just curious.
I know very little sed and better awk and I'd use the last one to do the job
# awk -F":" '{print $1":known_password:"$3":"$4":"$5":"$6":"$7":"$8":" } /etc/shadow > /etc/shadow_new
but how do you do the same job with sed?

Regards,

Andrea

[twistedbrain]

Originally Posted by twistedbrain

Just curious.
I know very little sed and better awk and I'd use the last one to do the job
# awk -F":" '{print $1":known_password:"$3":"$4":"$5":"$6":"$7":"$8":" } /etc/shadow > /etc/shadow_new
Andrea

Clearly this is only an example, because I'll have to manage the system accounts without passwords or with passwords to not change and "known_password" will be an encrypted known password.